Despite extensive research on materials for rechargeable Lithium-ion batteries in the last decades, graphite is still the most widely used anode material for commercial cells. However, graphite has a relatively low specific and volumetric capacity (372 mAhg−1; 820 mAhcm−3) compared to many alloying (e.g. Si, Ge, Sn) and conversion-type materials (e.g. Fe3O4, MoS2, SnSb). Although these materials suffer commonly from massive volume changes occurring during lithiation/delithiation, it has been demonstrated for a multitude of systems that this issue can be mitigated by using nanostructured materials.[1] Nevertheless, commercialization of such high-capacity alloying or conversion-type anodes has been hampered for several reasons. Especially for conversion-type anodes, often a major fraction of the capacity is obtained at potentials beyond 1.0 V vs. Li+/Li, resulting in low energy densities for the corresponding full-cells. Secondly, often synthesis of battery materials is too cost-intensive or too complicated to be implemented on the industrial scale. Among the few materials, which are realistic candidates to replace graphite in commercial cells is Sn, because it combines most of the crucial properties: high volumetric and specific capacities (˜7300 mAhcm−3, 992 mAhg−1), low delithiation potential, high electric conductivity and reasonable price. In fact, anodes based on an amorphous Sn—Co—C nanocomposite are currently being used in Sony's Nexelion™ battery which has triggered intensive research on Co—Sn based anodes for Lithium-ion batteries.[2]
Therefore, suitable materials to replace graphite as anode are urgently needed in order to improve the energy density of rechargeable battery, in particular Lithium-ion batteries, for increasingly important applications such as portable electronics or electric cars.
It is therefore necessary to develop a cheap and simple procedure that allows the production of MSnx nanoparticles showing high electrochemical performance as anode materials for rechargeable battery, in particular Lithium-ion batteries.